1. Field of the Invention
This application relates generally to the deposition of silicon-containing materials in semiconductor processing. More particularly, this application relates to the deposition of doped crystalline silicon-containing films using trisilane and incorporating electrically active dopants.
2. Description of the Related Art
The electrical properties of crystalline semiconductors such as silicon (Si), germanium (Ge) and alloys thereof (SiGe) are influenced by the degree to which the materials are doped with Group III and Group V dopants such as boron (B), indium (In), phosphorous (P), arsenic (As) and antimony (Sb). In general, higher levels of doping are generally correlated with lower resistivity. However, in practice doping is complicated by the tendency for the dopant to incorporate non-substitutionally, e.g., interstitially in domains or clusters within the silicon, rather than by substituting for silicon atoms in the lattice structure. Group III and Group V dopants are generally electrically active when incorporated substitutionally, but electrically inactive when incorporated non-substitutionally. Accordingly, doping typically entails extensive activation anneals that cause diffusion and move junctions in a manner that is difficult to control, consuming valuable thermal budget.
Doping of semiconductors with electrically active dopants is of considerable commercial importance in a variety of industrial applications, such as in semiconductor manufacturing, microelectromechanical systems (MEMS) device fabrication, and in flat panel displays. Thus, there is a need for improved methods to incorporate electrically active dopants into semiconductors.